Bubble Continuous Positive Airway Pressure (bubble-CPAP) is a widely used respiratory technology for premature neonates around the world. It is simple, effective and especially applicable in rural areas. Bubble-CPAP devices include a water column with a tube submerged in the water column, where the depth of the submerged tube indicates the backpressure delivered by the device. Physically, the tube is submerged in the water column, and air bubbles escape out of the bottom of the tube. Thus, within the tube and all associated piping of the bubble-CPAP, a backpressure directly proportional to the submerged depth of the tube is maintained. The Continuous Positive Airway Pressure (CPAP) recruits and stabilizes the infant's alveoli in their lungs. Results obtained using bubble-CPAP are comparable to results obtained using traditional ventilator CPAP. However, for infants suffering moderate to severe respiratory distress, CPAP (either ventilator or bubble) is inadequate. Variable level or Dual Positive Airway Pressure (Bi-PAP or NIPPV), consisting of a cyclic oscillation between the lower pressure (Positive End Expiratory Pressure or PEEP) and a higher pressure (Peak Inspiratory Pressure or PIP) may be utilized to recruit and stabilize the alveoli in infants with severe respiratory distress if CPAP is insufficient. This may be done with a conventional mechanical ventilator or other technology. However, due to the expense and complexity, it is not always possible to offer ventilator access to patients. Therefore, in the absence of mechanical ventilators or similar technologies, many patients with moderate to severe respiratory distress are not adequately treated.
BiPAP and Non-Invasive Positive Pressure Ventilation (NIPPV), the next levels of clinical respiratory treatment utilized to assist premature babies in breathing, involves a cyclic oscillation between the baseline pressure and a higher level. For example, typical BiPAP pressures may include oscillation between 8 cm and 5 cm of water pressure at a frequency of about 0.66 Hz, while NIPPV pressures may include oscillation between about 20 cm and 5 cm of water pressure at the same frequency. However, BiPAP and NIPPV are typically only available in more developed countries, using conventional mechanical ventilators or BiPAP machines. These devices are expensive, require additional continuous supply of electricity and are difficult to maintain and service. In some regions, large sectors of the population may not have access to ventilators or BiPAP machines. In the context of respiratory care, invasive treatment typically refers to the placement of a tube in the patient's trachea to assist with ventilation (“intubation”). Recently there has been increased interest in non-invasive forms of treatment, like bubble CPAP, to reduce damage to infant trachea and lungs. This is also particularly relevant for settings which may not have facilities for intubation. BiPAP or NIPPV is typically delivered as a noninvasive treatment in contrast to mechanical ventilation and can reduce hospital stay in comparison to standard CPAP or bubble-CPAP. In BiPAP or NIPPV devices, an oscillating pressure functions to recruit and stabilize alveoli, the functional units of the lungs. The modulating pressures produced by the BiPAP or NIPPV function are theorized to assist breathing and to remind the patient to breathe, facilitating a more rapid recovery.
In addition to use with neonates, BiPAP and NIPPV ventilation can be useful in treating patients of all ages, and can be used to provide respiratory assistance to patients with many different conditions. BiPAP and NIPPV are known treatments for many respiratory conditions, such as those arising from Congestive Heart Failure, Chronic Obstructive Pulmonary Disease and Asthma and are known to be useful for respiratory support during surgical procedures. These treatments are also commonly used in patients with sleep apnea.